package app

import (
	"context"
	"fmt"
	"strings"

	"gitea.nik4nao.com/nik/home-services/ha-gateway/internal/core/domain"
	"gitea.nik4nao.com/nik/home-services/ha-gateway/internal/core/ports/driven"
)

type EntityApp struct {
	ha driven.HAClient
}

// NewEntityApp constructs the entity application service.
func NewEntityApp(ha driven.HAClient) *EntityApp {
	return &EntityApp{ha: ha}
}

// GetState loads a single entity state through the HA driven port.
func (a *EntityApp) GetState(ctx context.Context, id domain.EntityID) (*domain.EntityState, error) {
	s, err := a.ha.GetState(ctx, string(id))
	if err != nil {
		return nil, err
	}
	return haStateToDomain(s), nil
}

// ListStates filters the full Home Assistant state list by explicit IDs and/or domain.
func (a *EntityApp) ListStates(ctx context.Context, ids []domain.EntityID, domainFilter string) ([]*domain.EntityState, error) {
	all, err := a.ha.ListStates(ctx)
	if err != nil {
		return nil, err
	}

	idSet := make(map[string]struct{}, len(ids))
	for _, id := range ids {
		idSet[string(id)] = struct{}{}
	}

	var out []*domain.EntityState
	for _, s := range all {
		if len(ids) > 0 {
			if _, ok := idSet[s.EntityID]; !ok {
				continue
			}
		}
		if domainFilter != "" {
			if !strings.HasPrefix(s.EntityID, domainFilter+".") {
				continue
			}
		}
		out = append(out, haStateToDomain(s))
	}
	return out, nil
}

// haStateToDomain stringifies raw Home Assistant attributes so the core model
// stays transport-agnostic and easy to serialize over gRPC.
func haStateToDomain(s *driven.HAState) *domain.EntityState {
	attrs := make(map[string]string, len(s.Attributes))
	for k, v := range s.Attributes {
		attrs[k] = fmt.Sprintf("%v", v)
	}
	return &domain.EntityState{
		EntityID:    domain.EntityID(s.EntityID),
		State:       s.State,
		Attributes:  attrs,
		LastChanged: s.LastChanged,
		LastUpdated: s.LastUpdated,
	}
}